Finding the Fourth Proportional to 81.63, 121.68 and 79.65
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Solution
The fourth proportional to 81.63, 121.68 and 79.65 is: 118.73
Step by Step Solution
- Step 1: Write the proportion equation
81.63 : 121.68 = 79.65 : x - Step 2: Convert to fraction form
81.63/121.68 = 79.65/x - Step 3: Cross multiply
81.63x = 121.68 × 79.65 - Step 4: Simplify right side
81.63x = 9,691.81 - Step 5: Solve for x
x = 9,691.81/81.63 - Step 6: Final answer
x = 118.73
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Why These Related Problems?
These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.